Spotlight On Vitamin B Complex

What are B Vitamins?

B vitamins are a group of water-soluble nutrients that play an important role in many aspects of body function. Although each B vitamin has its own unique functions, they also work synergistically. With the exception of vitamin B12 they are not stored in the body so need to be constantly replenished. The need for B vitamins increases during times of stress and illness.

Functions and Benefits of B vitamins

  •  Energy production
  • Digestion
  • Cardiovascular health
  • Protein, carbohydrate and fat metabolism
  • Mental health and nervous system function
  • Skin and hair health
  • Growth and development
  • Immune function

Let’s take a look at each B vitamin in turn:

 Thiamine ~ Vitamin B1

 Functions of Thiamine

  • Conversion of carbohydrates into energy
  • Involved in heart and cardiovascular system
  • Muscle contraction
  • Conduction of nerve signals
  • Metabolism of pyruvate

Deficiency Signs and Symptoms

A lack of thiamine can cause:

  • Weakness
  • Fatigue
  • Nerve damage

Deficiency is most often seen in people who abuse alcohol as alcohol interferes with the body’s ability to absorb thiamine from food. If alcoholics do not take in higher than the recommended amounts of thiamine they may end up with a disease called beriberi.

Food Sources of Thiamine

  • Wheat germ, beef, pork, trout, tuna, eggs, peas, beans, lentils, nuts and seeds

Riboflavin ~ Vitamin B2

Functions of Riboflavin

  • Growth
  • Red blood cell production
  • Release of energy from proteins
  • Health of the skin, eyes and nervous system

Deficiency Signs and Symptoms

  • Mouth or lip sores
  • Skin problems
  • Sore throat
  • Swelling of mucous membranes
  • Anaemia

Food Sources of Riboflavin

Dairy products, eggs, green leafy vegetables, oats, beef, mushrooms, liver, kidneys, legumes and nuts.

UV light can destroy riboflavin, so ideally these foods should be kept out of direct sunlight.

Niacin ~ Vitamin B3

Functions of Niacin

  • Release of energy from food
  • Health of the nervous system
  • Skin health
  • Digestive function

Deficiency Signs and Symptoms

Severe deficiency causes pellagra. Symptoms include:

  • Digestive problems
  • Inflamed skin
  • Poor mental function

Niacin and Hearth Disease

Doses of 1 to 3 grams of nicotinic acid per day is often used to treat high blood cholesterol. Niacin can help to increase levels of good cholesterol (HDL) and can reduce blood fats.

Niacin supplements can cause flushing and tingling. Tom Oliver B Complex contains niacin in the form of nicotinamide which does not cause flushing.

Food Sources

  • Meat, fish, poultry, eggs, dairy products, rice, legumes and peanuts.

Pantothenic Acid – Vitamin B5

Functions of Pantothenic Acid

  • Release of energy from food
  • Growth
  • Production of hormones and cholesterol
  • Synthesis of Co-enzyme A which is involved in anabolic and catabolic processes
  • Metabolism of carbohydrate, fat and protein

Deficiency Signs and Symptoms

  • Numbness, tingling or burning of the hands and feet
  • Headache
  • Fatigue
  • Irritability or restlessness
  • Disturbed sleep
  • Gastrointestinal disturbances

Food Sources

  • Chicken, beef, potatoes, oats, tomatoes, eggs, broccoli, legumes, yeast and whole grains.

Pyridoxine – Vitamin B6

Functions of Pyridoxine

  • Production of antibodies needed by the immune system.
  • Nerve function
  • Production of haemoglobin which carries oxygen in the blood to the tissues.
  • Break down of proteins
  • Energy production
  • Blood sugar control
  • Metabolism of homocysteine

Deficiency Symptoms

  • Confusion
  • Depression
  • Irritability
  • Mouth and tongue sores also known as glossitis
  • Peripheral neuropathy

Food Sources

  • Tuna and salmon, bananas, legumes, beef, pork, poultry, nuts, whole grains.

Biotin – Vitamin B7

Functions of Biotin

  • Conversion of food into energy
  • Skin, hair and nail health
  • Energy production
  • Needed for enzymes involved in carbohydrate, fat and protein metabolism
  • Blood sugar control

Deficiency Signs and Symptoms

  • Muscle pain
  • Dermatitis or skin rashes
  • Glossitis (swelling of the tongue)
  • Hair loss
  • Brittle nails
  • Fatigue

Food Sources

  • Chocolate, eggs, legumes, nuts, liver, kidneys, pork, yeast, leafy greens, mushrooms.
  • Biotin is made by some gut bacteria

Folate or Folic acid ~ Vitamin B9

Functions of Folate

  • Formation of healthy red blood cells
  • Reduce the risk of neural tube defects, such as spina bifida, in unborn babies
  • Prevention of folate deficiency anaemia
  • Production of DNA and other genetic material
  • Cell division
  • Metabolism of homocysteine

Deficiency Signs and Symptoms

  • Megaloblastic anaemia which causes weakness, fatigue, poor concentration, headaches, heart palpitations, shortness of breath
  • Sore tongue and mouth
  • Changes in the colour of the skin, hair or fingernails.

Folate and Pregnancy

If you're pregnant, trying for a baby or could get pregnant, it's recommended that you take a 400 micrograms of folic acid daily until you're 12 weeks pregnant. Folic acid supplements need to be taken before you get pregnant, so it’s advisable to take them if there's a chance you might get pregnant. This is to help prevent birth defects, such as spina bifida, in your baby.

Food Sources

  • Broccoli, leafy green vegetables, asparagus, liver (avoid during pregnancy), beans, peas, oranges, nuts, peanuts.


Taking large doses of folate supplements might hide a vitamin B12 deficiency.

Vitamin B12 – Cobalamin

Vitamin B12 exists in several forms and contains the mineral cobalt, so compounds with vitamin B12 activity are collectively called cobalamins.

Functions of Vitamin B12

  • Production of red blood cells
  • Health of the nervous system
  • DNA synthesis
  • Release of energy from food
  • Works with folate
  • Metabolism of homocysteine

Deficiency Signs and Symptoms

  • Megaloblastic anaemia with symptoms of fatigue and weakness
  • Constipation
  • Loss of appetite and weight loss
  • Numbness and tingling of the hands and feet
  • Poor balance
  • Depression
  • Confusion
  • Sore mouth and tongue
  • In infancy deficiency can lead to failure to thrive.

Food Sources

  • Animal foods including meat, fish, dairy products, eggs, nutritional yeast.

Vitamin B12 can interact with some medications and some medicines can interfere with B12 absorption. Vegans are likely to need to supplement with vitamin B12 as it is not found in a bio-available form in plant foods.


Functions of Choline

  • Brain function
  • Muscle control
  • Cell membranes
  • Cardiovascular health

Deficiency Signs and Symptoms

  • Muscle and liver damage
  • Deposits of fat in the liver (a condition called nonalcoholic fatty liver disease)

Food Sources

  • Meat, eggs, poultry, fish, dairy products, potatoes, cruciferous vegetables, beans, nuts, seeds, whole grains.

Inositol – Vitamin B8

Inositol is a water-soluble vitamin-like structure commonly called vitamin B8, yet it’s not strictly a vitamin as it can be synthesised in the body and is closely related to glucose.

Functions of Inositol

  • Component of cell membranes
  • Found in the heart, liver and muscles
  • Functions as a neurotransmitter and supports other neurotransmitters such as dopamine, GABA and serotonin making it useful in treating depression and mood disorders
  • Aids mental health, memory and cognitive function
  • Helps regulate gene expression
  • Blood sugar regulation, insulin sensitivity and lipid metabolism
  • Supports liver health.

Deficiency Signs and Symptoms

  • Nerve related conditions
  • Cognitive imbalances
  • Depression or mood disorders
  • Sleep disorders
  • Hair loss
  • Constipation

Food Sources

  • Cantaloupe melon, citrus fruits, seeds, whole grains, pulses, nuts, yeast, liver, brown rice, soy beans and green leafy vegetables.

Caffeine and antibiotics can decrease the amount of Inositol in the body so if you regularly consume lots of caffeine or are on antibiotics for a prolonged period of time an Inositol supplement could be advisable.

Para Amino Benzoic acid (PABA)

PABA is an organic compound that can be synthesized in the body by gut bacteria and is therefore considered a nonessential nutrient in humans. Long term use of antibiotics may cause an imbalance in the gut bacteria which may, in turn, lead to a deficiency in PABA.

Functions of PABA

  • Skin health
  • Hair health
  • Digestive health
  • Synthesis of folic acid

Deficiency Signs and Symptoms

  • Skin conditions such as premature wrinkling and eczema.
  • Chronic digestive disorders such as constipation
  • Poor hair condition

Food Sources

  • Organ meats such as kidney and liver, mushrooms and whole grains.

Who may benefit from supplemental B vitamins?

  • Pregnant or lactating women
  • People recovering from surgery
  • People with genetic mutations
  • People taking certain medications such as proton-pump inhibitors, antacids or antibiotics
  • Those on a restricted diet for cultural, ethical or medical reasons
  • People with poor absorption or digestive issues such as coeliacs or those with IBD or IBS
  • People under stress
  • Older people
  • Vegans, in particular, need B12
  • People who drink a lot of alcohol
  • Those who have had gastrointestinal surgery
  • People with pernicious anaemia
  • Those with cardiovascular disease or high homocysteine
  • People with depression or mood disorders

Tom Oliver’s Vitamin B Complex

Tom Oliver’s vitamin B complex contains a balance of all the B vitamins: Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic acid (B5), Pyridoxine (B6), Biotin (B7), Folic Acid (B9), and B12, as well as choline, inositol and PABA which aid liver function, energy production, skin health and mental health.

[Shop Tom Oliver's Vitamin B Complex]

Always talk to your health care provider before taking any supplements, especially if you are on medication or have a medical condition. 

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